Overview

A fundamental innovation in the area of wireless sensor networks has been the concept of data-centric networking. In a nutshell, the idea is this: routing, storage, and querying techniques for sensor networks can all be made more efficient if communication is based directly on application-specific data content instead of the traditional IP-style addressing [74].

Consider the World Wide Web. When one searches for information on a popular search site, it is possible to enter a query directly for the content of interest, find a hit, and then click to view that content. While this process is quite fast, it does involve several levels of indirection and names: ranging from high-level names, like the query string itself, to domain names, to IP (internet protocol) addresses, and MAC addresses. The routing mechanism that supports the whole search process is based on the hierarchical IP addressing scheme, and does not directly take into account the content that is being requested. This is advantageous because the IP is designed to support a huge range of applications, not just web searching. This comes with increased indirection overhead in the form of the communication and processing necessary for binding; for instance the search engine must go through the index to return web page location names as the response to the query string, and the domain names must be translated to IP addresses through DNS. This tradeoff is still quite acceptable, since the Internet is not resource constrained.

Wireless sensor networks, however, are qualitatively different.